#include <iostream>
#include <string>
using namespace std;

class A {
    static int a;

   public:
    void change(int i) {
        a = i;
    }
    void value_of_a() {
        cout << a;
    }
};

int main(int argc, char const *argv[]) {
    A a1 = A();
    a1.change(5);
    a1.value_of_a();
    return 0;
}